Sanitary waste disposal unit

ABSTRACT

A sanitary waste disposal unit ( 1 ) including a scalable destruction chamber ( 11 ), a vacuum pump ( 23 ), a source of heat ( 15 ) and means ( 29 ) for the controlled introduction of air into the chamber ( 11 ). In use the waste is introduced on the chamber ( 11 ) which is then evacuated to remove substantially all the oxygen, and heated to sterilize the waste material to approximately 300-500° C. The chamber ( 11 ) is then cooled to approximately 150° C., a temperature sufficiently high enough to allow combustion of the waste material, which has been partially carbonized. A limited quantity of air is introduced into the chamber allowing combustion of the waste material and the combustion products are removed from the chamber.

TECHNICAL FIELD

The present invention relates to a sanitary waste disposal unit.

BACKGROUND OF THE INVENTION

The current and planned regulations regarding “Duty of Care” to the safetreatment and disposal of all blood products relates directly to theirtreatment and disposal at sea. Furthermore, the sanitary waste can anddoes block drains, particularly small diameter systems which areincreasingly being fitted. It can also fail to be destroyed in septictanks, cause difficulties in sewage treatment plants and fail to sinkwhen disposed of at sea.

SUMMARY OF THE INVENTION

The object of the present invention is to provided a unit for disposingof sanitary waste.

According to the invention there is provided a sanitary waste disposalunit comprising:

a destruction chamber which is openable for reception of sanitary wasteand closable for evacuation;

means for evacuating air from the destruction chamber;

means for heating the chamber when evacuated; and

means for a controlled introduction of air into the heated evacuationchamber for combustion of sanitary waste heated in the chamber.

In use:

1. the sanitary waste is introduced to the chamber;

2. the chamber is evacuated to remove sufficient oxygen to avoidcombustion;

3. the chamber and the contained waste is heated to sterilise the waste;

4. the chamber and contents is cooled to a temperature stillsufficiently high for the material to combust;

5. air is introduced into the chamber to allow combustion of thematerial;

6. the chamber is emptied.

The destruction chamber can be emptied by flushing with water or byapplication of a vacuum.

The means for evacuation means may be a vacuum pump incorporated in thesanitary waste disposal unit. Alternatively the evacuation means may bea connection to a vacuum system of a ship or building in which the unitis installed.

Normally the destruction chamber will be arranged beneath a receptionchamber for additional waste to be stored in if the unit is alreadyprocessing waste.

For the avoidance of odours escaping from the unit, the destructionchamber may be kept at reduced pressure even when not operational.Additionally or alternatively a deodoriser may be introduced into thechamber.

BRIEF DESCRIPTION OF THE DRAWINGS

To help understanding of the invention, a specific embodiment thereofwill now be described with reference to the accompanying drawing, inwhich:

FIG. 1 is a cross-sectional side view of a sanitary waste disposal unitof the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The unit 1 has a case 2 of sheet steel 3 lined with insulating material4. The case has an open base 5 with a protective mesh 6. A lid 7 hingedat one side 8 to the case has louvres 9 and a handle 10.

Mounted within the case 2 is a vacuum chamber 11 of stainless steel. Ithas a tapered bottom 12 leading to a shut off valve 13. Beyond thevalve, the unit is plumbed 14 to a soil pipe (not shown). The vacuumchamber has ohmic with heaters 15 attached to its side walls. At the topof the walls, an insulating ceramic ring 16 is provided and above this asimilar, reception chamber 17 extends up. A closure member 18, fastenedto the underside of the lid 7 closes the top of the reception chamber.

A pair of flaps 19 are hinged at the bottom of the reception chamber foropening downwards to allow waste material in the reception chamber tofall into the vacuum chamber. The ring 16 has three points 20, 21, 22.The first point 20 leads to a vacuum pump 23, whose outlet is plumbed 24to the non-shown soil pipe. A filter 30, between the chamber 11 and thevacuum pump 23 protects the vacuum pump from any tar and other depositsproduced by the waste material on heating the filter is typically a tarremoving filter. This vacuum pump may be a stand alone pump, or may be aships vacuum system. The second pipe 21 leads to an air valve 25 havingan inlet 26 within the case 2. The third port 22 has a water valve 27 towhich a water supply 28, typically sea water on board ship leads.

The unit is controlled by a control unit 29, which specifically controlsthe outlet valve 13, the heaters 15, the vacuum pump 23, the air inletvase 25 and the water inlet valve 27.

In use the lid 7 is lifted and waste material is dropped into thereception chamber 17. On re-closure of the lid, the flaps 19 are openedby a non-shown handle. The waste material drops into the vacuum chamber11 and the flaps 19 are closed by springs 30. A non-shown interlockprevents their opening prior to completion of the destruction cycle. Thecontrol unit is initiated.

The pump 23 is started and draws a vacuum in the vacuum chamber. Theheaters 15 are switched on and the contents of the vacuum chamber, butnot of the reception chamber 17 due to the insulating ring 16, areheated. The heating, typically to 300-500° C., drives off any volatilematerial in absense of oxygen, whereby the risk of explosive ignition isavoided. The volatiles are drawn by the pump 23 to the soil pipe. Atthis stage some of the waste has been at least partially converted tocharcoal. After a safe period of time, the heaters are switched offafter the chamber has cooled, as measured by a thermocouple 31, to 150°C., the air valve 25 is opened to admit air for combustion of the waste.The vacuum pump continues to draw gas, including the products ofcombustion, from the vacuum chamber and pass these to the non-shown soilpipe. The filter 30 prevents the tar and other solid residues fromcollecting in the soil pipe. Again after a period of time suitable forreasonably complete combustion, the waste material that is leftcomprises a few charred remains. The air valve and the vacuum pump areisolated and the chamber is flushed out to the soil pipe by opening ofthe water valve 29. Alternatively the waste may be removed from thechamber by vacuum to the soil pipe 14. After a suitable period, theentire cycle can be repeated. If necessary, further waste material canbe added to the reception chamber prior to completion of the cycle. Itis processed in a new cycle after completion of the previous one.

Occasionally, to clean the waste disposal unit, water is introduced intothe chamber 11 and the heaters 15 are switched on. After a few minutesthe heater are switched off and the chamber is emptied. In theembodiment shown, where the chamber is emptied by flushing with water,it is the flushing water which is introduced into the chamber forcleaning. Alternatively where the chamber is emptied by the applicationof a vacuum, the cleaning water will be loaded into the chamber throughthe lid 7, and emptied by the application of vacuum.

What is claimed is:
 1. A method of destruction of sanitary wastecomprising the steps of: introducing waste material into a destructionchamber; evacuating the chamber to remove sufficient oxygen to avoidcombustion; heating the chamber and the contained waste material tosterilise the waste material; cooling the chamber and contents of thechamber to a temperature still sufficiently high for combustion of thematerial; introducing air into the chamber to allow combustion of thewaste material; and emptying the chamber.
 2. A method as claimed inclaim 1, wherein the chamber is heated to a temperature of 300-500° C.3. A method as claimed in claim 2, wherein the chamber is cooled to atemperature of approximately 150° C. before the introduction of air. 4.A method as claimed in claim 3, wherein the chamber is emptied byflushing with water.
 5. A method as claimed in claim 3, wherein thechamber is emptied by application of a vacuum to its base.
 6. A methodas claimed in claim 5, including the introduction of a deodoriser to thechamber.
 7. A sanitary waste disposal unit comprising: a destructionchamber which is openable for reception of sanitary waste and closablefor evacuation; means for evacuating air from the destruction chamber;means for heating the chamber when evacuated; and means for a controlledintroduction of air into the heated evacuated chamber for combustion ofsanitary waste heated in the chamber, wherein the sanitary wastedisposal unit is adapted and arranged to control the evacuation means tomaintain the destruction chamber between ambient pressure and thepressure to which the chamber is reduced during heating even when notoperational to prevent odours from escaping the chamber.
 8. A sanitarywaste disposal unit as claimed in claim 7, wherein the destructionchamber is arranged beneath a reception chamber for storage ofadditional sanitary waste while the destruction chamber is in operation.9. A sanitary waste disposal unit as claimed in claim 8, including meansfor emptying combustion residue from the destruction chamber with water.10. A sanitary waste disposal unit as claimed in claim 8, includingmeans for emptying combustion residue from the destruction chamber byvacuum at a base of the chamber.
 11. A sanitary waste disposal unit asclaimed in claim 10, wherein the evacuation means is a vacuum pumpincorporated in the sanitary waste disposal unit.
 12. A sanitary wastedisposal unit as claimed in claim 10, wherein the evacuation means is aconnection to a vacuum system of a ship or building in which the unit isinstalled.
 13. A sanitary waste disposal unit as claimed in claim 12,including a filter between the chamber and a vacuum pump to capture anytar and other combustion products.
 14. A sanitary waste disposal unit asclaimed in claim 13, including means for the introduction of adeodoriser into the destruction and/or reception chambers.
 15. Asanitary waste disposal unit as claimed in claim 14, wherein heatingmeans are ohmic heaters attached to side walls of the destructionchamber.
 16. A sanitary waste disposal unit as claimed in claim 15,wherein the heating means is adapted to heat to a temperature of300-500° C.